Most commercial properties include a number of building systems that monitor and regulate various functions of the building for the comfort and well-being of the tenants. These building systems include security systems, fire control systems, and elevator systems. One prevalent and important building system is the environmental control system.
An environmental control system is used to regulate the temperature and flow of air throughout a building. The air conditioning for a building typically includes one or more chillers for cooling air and one or more heaters for warming air. Fans distribute air conditioned by a chiller or heater into a duct system that directs the flow of air to the various rooms of a building. Dampers are located within the duct system to variably control an opening to a branch of a duct system or to a room. The dampers are maneuvered through a range of movement from being 100% open to 0% open, i.e., closed, by actuators. Also, the speed of a motor that drives a fan is controlled to regulate fan speed and, correspondingly, air flow in the system. An important component of a building environmental system is the control system that varies the fan motor speed and the position of the various dampers to maintain pressure and flow rate set points for the system.
Control systems for building systems are increasingly reliant upon computer and network technology. Micro-controllers and the like may be used to operate and maintain actuators for damper position as well as controlling fan speed. These local controllers provide operational data to an overall system controller. The overall system controller is typically a computer that analyzes data received from local controllers to determine whether system parameters, such as set points, are being maintained. If the system parameters are not being met, the system controller issues command messages to one or more local controllers to adjust local control so the system parameters may be achieved. In some previously known systems, the system controller communicates with the local controllers over a computer network. Most typically, the hardware platform for the network is an Ethernet platform and the network software supporting communication over the network is a TCP/IP layer. This structure supports communication between a control application program executing on the system controller and an application program executing on the local controller. However, the computer network does not provide remote building system engineers with access to the application programs.
In order to monitor a building system, a system controller typically receives status data from local controllers periodically or as conditions change. These data may be analyzed by the system controller to determine whether commands for local controllers should be generated and then discarded or stored after being analyzed. These stored data may be characterized as historical data for the building system. These historical data may be very useful for determining response characteristics of a building system or for other system modeling uses. However, these historical data are typically stored at the building site. Consequently, these data are inaccessible to building system engineers unless a copy of these data are generated and migrated to another location for analysis and modeling purposes. Additionally, previously known systems require the system controller to store the operational data in a database. Thus, the system controller absorbs an administrative overhead for managing the storage of operational data in a local database. This administrative overhead may include programming logic to convert data values to a common format or to manipulate the application programming interface (API) of a database.
In an effort to reduce this administrative overhead, systems have been developed that segregate the informational aspects of a building control system from the control aspects. For example, U.S. Pat. No. 6,141,595 discloses a system that includes an information layer and a control layer that interface with a group of databases. The control layer enables control applications to access attribute data for the purpose of operating control devices in a building. Optimization applications update the control attributes for improved control of the building system. The information layer supports communication with applications through the Internet or other network interfaces so external users may access the data in the databases. The control and optimization applications, on the other hand, query the databases through their respective APIs. Thus, control and optimization application developers need to be able to program the access methods for the various databases into their applications. The control layer provides a standardized interface for the control and optimization applications to the components of the building system.
While the system of the '595 patent separates external user communication with the databases from the control and optimization application communication with the databases, it still requires the control and optimization application developers to program database access methods in the applications. Consequently, the building engineers are required to be knowledgeable regarding a variety of database APIs. Furthermore, the control and optimization applications are not readily accessible to the external users. Also, the system of the '595 patent assumes that the control and optimization applications are tested and fully developed before being installed between the control layer and the system database APIs. However, the system of the '595 patent does not provide an environment for accessing data to model and to test an application before being installed on the system.
In addition to the data limitations of previously known systems, there are other issues that compound the problem of developing applications for building systems. Typically, companies that manage buildings have to somehow obtain the programs for controlling a building system from an outside source. Otherwise, the building manager would need to keep a team of system engineers and programmers for application development. The system engineers understand the building system components and develop control algorithms and load predictors for control of the system. However, they typically do not have adequate knowledge of software methodologies and programming techniques to generate and test computer programs efficiently. Likewise, the computer programmers and software engineers are able to design, develop, test, and integrate computer programs but they do not possess the building system expertise to appropriately apply control theory to building system components. Typically, however, companies that manage building systems do not have sufficient resources to support a team of system engineers and software engineers. Accordingly, they employ a staff of technicians to maintain and operate the building system components and seek to obtain the application solutions for their system needs from outside sources.
One way in which building management companies may seek to obtain application solutions is to purchase general purpose control programs for systems comprised of components similar to the ones in a particular building system. However, no such general purpose solution exists as the uniqueness of building system topology, component composition, and other factors make it impracticable to develop and adapt a general solution for most building system needs efficiently.
Another way to obtain application solutions is to procure the services of an building system engineering service. Typically, these companies employ both building system engineers and computer engineers for developing and testing application solutions for building systems that are owned and operated by one or more building management companies. The obstacles to the development and testing of application solutions for different building systems are significant. For one, building systems use different types of controllers, actuators, and networks for communicating between building system components. As a result, the computer engineers need to be able to write programs in a variety of control program languages and implement controls for and obtain data from a plethora of devices that require commands and supply data in different formats. Additionally, the computer engineers must be able to work with system engineers to convert the control algorithms and load predictors designed by the system engineers into computer software. This human interface may require an extensive amount of time and significant expenditure of resources to take a building system solution from its system design to implementation in a building system. This expenditure is especially exacerbated when, for example, system engineers who specialize in load prediction and system engineers who specialize in HVAC systems both need to have their designs implemented by the same computer engineering team for a building system. This need puts pressure on the computer engineering team to develop expertise for writing software in different operational fields without proven expertise in each of those fields.
One way that a computer engineering team meets these types of needs is to obtain various software packages from software vendors and then adapt them for implementing a piece of an application solution. For example, a neural network package may be purchased and adapted to implement a load forecasting component of a building system solution. Another package that may be required is a data base management system for storing and querying data required for application solution support. Other packages may include data computational programs for various building system parameters and other engineering tools for particular building systems. However, one problem with this approach is the need to integrate disparate packages that may be programmed in different languages operating on different platforms. Latency and data compatibility issues may arise during the integration efforts.
What is needed is a system for facilitating the development of application solutions with reduced compatibility issues.
What is needed is a system for developing application solutions that does not require implementation of solution components in a variety of computer languages.
What is needed is a system for reducing the need for human interaction in translating a system engineering design into an operational solution.
What is needed is a system that provides support for diverse fields of operational expertise.
What is needed is a system for developing control applications without requiring knowledge of a database API being programmed into the application.
What is needed is a system for developing control applications that permit the real-time and historical data for a building system to be used for application modeling and testing without requiring the installation of the application in the system.
What is needed is a way to enable external users to access applications.